Locking device for a bracelet or necklace

ABSTRACT

A locking device for bracelets and necklaces having two ends, each provided with a chain link, includes a first plate and a second plate which are pivotably coupled together for movement about a common pivot axis between an opening and locking position. The plates each have an aperture formed therethrough aligned with the pivot axis through which one of the chain links may extend and the first plate has a hook-like end portion for receiving the other of the chain links. The second plate has an arcuate slot formed therein running in a concentric manner with respect to the pivot axis which defines an arched portion on an end portion of the second plate disposed distal to the pivot axis relative to another end portion thereof. The arched portion also runs concentrically with respect to the pivot axis and, in the locking position, is received through the other chain link received in the hook-like end portion of the first plate.

The invention relates to a locking device for a bracelet or necklace,whereby the two ends are provided with a chain link.

The best known chain link locking device consists of a slotted, hollowring coupled to one end of the chain and an eyelet coupled to the otherend of the chain. This eyelet is so shaped that it can be introducedinto the ring. In order to prevent the eyelet from involuntarily oraccidentally being removed from the slotted ring, an arch-like lockingelement is provided within the ring which, under pre-tension, bridgesthe slot or interruption in the ring by means of a spring element. Foropening the locking device, the arch-like piece can be displaced intothe hollow ring.

It is an object of the invention to provide a locking device of theaforementioned type which simplifies manufacture, is easy to use and isable to respond to stress exerted with relative large forces.

The inventive locking device is characterized by the provision of twoplates which are pivotably coupled together for movement about a commonpivot axis. Both plates are provided with an aperture through each ofwhich the pivot axis and one of the end chain links extends. The firstplate has a hook-shaped portion or part for receiving the other endchain link and the second plate has a slot formed therein which isconcentrically positioned with respect to the pivot axis and whichdefines an arched piece which extends from the end of the second platewhich is disposed distal to the pivot axis. This arched piece also runssubstantially concentric with respect to the pivot axis and, in thelocked position of the locking device, penetrates the end chain linkreceived on the hook-shaped part of the first plate.

The subject matter of the invention will be explained in the followingwith reference to the drawings which illustrate some examples.

In the drawings:

FIG. 1 is a side elevational view of a first embodiment of the lockingdevice in accordance with the invention, shown in an open position;

FIG. 2 is a view similar to that of FIG. 1, but showing the lockingdevice in a locked position;

FIG. 3 is a sectional view taken along line III--III of FIG. 2;

FIG. 4 is a side elevational view of a second embodiment of theinventive locking device, shown in an open position; and

FIG. 5 is a view similar to that of FIG. 4, but showing the lockingdevice in a locked position.

Referring now in detail to the drawings, FIGS. 1 to 3 illustrate a firstembodiment of the inventive locking device, showing the device in theopen position, a locked position, and in a sectional view, respectively.The locking device acts as a releasable coupling of the two ends of abracelet or necklace 1 of which only the end portions are shown in FIGS.1 and 2. The bracelet or necklace may be any given piece of jewelry withthe only prerequisite being that at each end of the same a chain link 2,3 is present.

Essentially, the locking device comprises a first plate 4 and a secondplate 5 having an aperture 6 through which a hollow-type rivet 7extends, so that the plates are pivotable relative to each other arounda pivot axis, perpendicular thereto. The end of the first plate 4 whichfaces away from hollow-type rivet 7 has a hook-like shape. A chain link2 may be inserted or released through a guide slot 8. At least a portionof the guide slot 8 runs radially with respect to the mentioned pivotaxis. End portion or part 9 which forms the hook of the first plate 4 isat no place wider than the largest inner diameter of chain link 2, sothat the insertion and release of the same can be accomplished withoutcausing any difficulties. At the end opposite to the hollow-type rivet7, second plate 5 is provided with a slot 10 running concentrically withrespect to the mentioned pivot axis. The outer end of second plate 5 isprovided with an arched piece or portion 11.

When locking the locking device the arched piece 11 is placed into thechain link 2 which is inserted into the hook-like part 9 of first plate4, as can be seen in FIG. 2. Preferably, chain links 2 and 3 are oblongchain links, the inside breadth or diameter of which is larger than thesum of the widths of the two plates 4 and 5. Guide slot 8 in first plate4 and slot 10 in second plate 5 are so arranged that the closed endsections in the locked position of the plates overlap (see FIG. 2),whereby the free opening cross section is penetrated by a portion ofchain link 2.

When the guide slot 8 and the slot 10 are correctly positioned thepulling force exerted on the locking device is evenly distributed toboth plates. This results in a relatively high stress on the lockingdevice. Preferably, second plate 5 is provided with a projection 12directed against first plate 4, which is so arranged that thisprojection extends into the radial running portion of guide slot 8 andinto the first plate 4, in the locked position, as shown in FIG. 3.

Slot 10 may be deflected at a right angle at its closed end with respectto the position shown in FIG. 2, provided that the guide slot 8 is alsosomewhat longer. In this way, a positive locking is obtained whichcannot release itself as long as the locking device is subjected totension.

A further embodiment of the inventive locking device is shown in FIGS. 4and 5. This example shows that the shape of the plates may be adjustedto fashionable requirements. This locking device comprises a firstessentially heart-shaped plate 13 and a second essentially heart-shapedplate 14. The two plates 13 and 14 are pivotably coupled with each otherby means of a hollow-type rivet 15. The one end chain link 3 extendsthrough the hollow-type rivet 15 and the other end chain link 2 isinserted into a hook-like part 16 of the first plate 13. The hook-likepart 16 is obtained by providing a guide slot 17 which runs radiallywith respect to hollow-type rivet 15 in first plate 13. Second plate 14is provided with a slot 18 which runs concentrically with respect tohollow-type rivet 15. An arched piece 19 of second plate 14 extendssubstantially parallel to the slot. The closed end of slot 18 is heartshaped for further ornamentation.

Instead of hollow-type rivet 7 or 15 in second plate 5 or 14, anaperture may be punched which engages a protruding edge of the adjacentside of plate 4 or 13, whereby the edge penetrates the aperture 6 in thefirst plate 4 or 13 and is provided with an outer flange on the rearside of the first plate, for example.

The above described locking device is particularly suitable for jewelry,e.g., bracelets and necklaces. The device may be made of metal, forexample, silver, gold, or alloys thereof.

The above described locking device can also be used for locking belts orat any place where band-like elements are present which have to becoupled by means with eyelets. The locking device may also be made ofplastic materials.

What is claimed is:
 1. A jewelry clasp for bracelets and necklaceshaving two ends, each provided with a chain link, comprising:a firstplate and a second plate, which are pivotably coupled together formovement about a common pivot axis between an opening and lockingposition, said plates each having an aperture formed therethroughaligned with said pivot axis through which one of the chain links mayextend, said first plate having a hook-like end portion which defines aguide slot for receiving the other of the chain links and said secondplate having an arcuate slot formed therein having a portion running ina concentric manner with respect to the pivot axis which defines anarched portion on an end portion of said second plate disposed distal tothe pivot axis relative to another end portion thereof which archedportion also runs generally concentrically with respect to the pivotaxis and which, in said locking position, is received through said otherchain link received in said guide slot of said hook-like end portion ofsaid first plate, said guide slot of said first plate having a firstportion opening onto an edge of said first plate which runs in agenerally non-radial direction relative to said pivot axis and a secondportion which merges with said first portion and which runssubstantially in a radial direction relative to said pivot axis andwhich, in said locking position, crosses said arcuate slot of saidsecond plate to define a single open area of overlap through which saidother chain link may extend, said area of overlap lying exclusively inthe radially running and the concentrically running portions of saidguide slot and arcuate slot, respectively said area of overlap having across-section closely equal to the cross section of said other chainlink, and said areas of overlap being located at the terminal closed endof each slot.
 2. The clasp according to claim 1, wherein said plates aresubstantially congruently-shaped.
 3. The clasp according to claim 1,wherein in order to obtain a ratchet effect, said second plate isprovided with a projection on a side thereof adjacent to said firstplate which, in the locking position, snaps into the radial runningportion of said guide slot.
 4. The clasp according to claim 1, whereinsaid plates are pivotably coupled together by means of a hollow-typerivet.
 5. The clasp according to claim 1, wherein said arcuate slot runsexclusively in a concentric manner with respect to said pivot axis.